(a) Field of the Invention
The present invention relates to a current regulator drive circuit shunting current by voltage-dividing load, wherein a main load and a voltage-dividing load connect in series, a power control unit connects in parallel with a voltage-dividing load, and a voltage detector is installed at input ends of an AC or DC power source, or at two ends of one of the main load and the voltage-dividing load or the total load of the two loads connected in series, and/or a load current detector is installed at output end of the power source or at load end, depending on signals detected by the voltage detector and/or the current detector, if the voltage detected by the voltage detector and/or the current detected by the current detector is lower than a predetermined value, the power control unit is operated to perform shunt regulation of pulse width modulation (PWM), shunt regulation of conductive phase angle, or shunt regulation of switch type turn-on or cut-off, or to regulate the impedance of the power control unit, to increase the current passing through the main load; and if the voltage detected by the voltage detector and/or the current detected by the current detector is higher than a predetermined value, the power control unit is operated to perform shunt regulation of pulse width modulation (PWM), shunt regulation of conductive phase angle, or shunt regulation of switch type turn-on or cut-off, or to regulate the impedance of the power control unit, to decrease the current passing through the main load.
(b) Description of the Prior Art
The conventional control method for limiting the current of the load driven by AC or DC power is often to turn on or cut off the switch connected with the load in series for current limiting regulation; when the ON-OFF control over the switch is implemented, the current change is significant, thus the shortcomings include that the lamps will show changes in light and shade if the load is lighting instrument, and electromagnetic interference is formed if the control over high frequency PWM is implemented.